Is "harlot" considered to be a derogatory word?

Solution 1:

The following extract can help in understanting its usage:

Harlot is an old-fashioned word for a prostitute — a woman who has sex for money.

These days, calling a woman a harlot is usually done humorously. This word is too old-sounding and unusual to be very insulting. Still, you shouldn't call anyone a harlot, because it's a term — just like "whore," "strumpet," and "lady of the night" — for a woman who has sex for money. That's never been a compliment, even though today the world's oldest profession has a much nicer term: sex worker.

Vocabulary.com

The term has a long history,

c. 1200 (late 12c. in surnames), "vagabond, man of no fixed occupation, idle rogue," from Old French herlot, arlot "vagabond, tramp, vagrant; rascal, scoundrel. Used in positive as well as pejorative senses by Chaucer; applied in Middle English to jesters, buffoons, jugglers, later to actors. Secondary sense of "prostitute, unchaste woman" probably had developed by 14c., certainly by early 15c., but this was reinforced by its use euphemistically for "strumpet, whore" in 16c.

Etymonline